1. Field of the Invention
This invention relates to an infrared light designed for use with infrared imaging equipment. Specifically, the invention is directed to an infrared light which uses fiber optic cable to distribute the infrared light for improved visibility over the prior art.
2. Description of the Related Art
During covert aircraft night operations, all visible lighting systems on the aircraft are normally turned off to minimize the risk of detection. To compensate for the lack of visible lighting, the aircraft crew uses an infrared imaging system typically referred to as a xe2x80x9cnight vision imaging systemxe2x80x9d (NVIS). Night vision imaging systems are designed to amplify infrared light, which is undetectable to the naked eye, and provide a visible display to the user. The invention provides covert anticollision lighting capability when the aircraft""s visible lights are turned off by providing an infrared light visible to night vision imaging systems but not to the naked eye.
Infrared lighting systems have previously been installed on aircraft for this purpose, but they suffer from a number of disadvantages. Many require difficult and expensive modification of the aircraft. Other systems are difficult to service. Most importantly, prior systems suffer from insufficient lighting capability due to the nature of the infrared light sources. Infrared light sources are typically solid-state and provide only a small point of light that is easily obstructed. To compensate for this drawback, prior systems use a multitude of light sources. This large number of light sources increases the amount of electrical power required to operate the light, and also adds weight and complexity. There is a need for an infrared light which provides sufficient infrared lighting capability without resorting to a multitude of light sources.
This invention is directed to an infrared light that provides sufficient infrared lighting capability without the need for a multitude of infrared light sources. The present invention is designed for use as an anticollision light on an aircraft.
Specifically, the present invention includes a low-profile housing structure which minimizes wind resistance. The low-profile housing further includes a sidewall comprised of a series of surfaces of varying length to distribute the infrared light. The low-profile housing structure can also include an opening sized to allow the body of a visible strobe light to pass through the low-profile mounting structure, permitting collocation of the visible strobe light and the infrared light on the aircraft. The low-profile housing structure may also include a recess shaped such that the visible strobe light retains and secures the infrared light between the visible strobe light and the aircraft. It should be noted that while the opening and recess provide a convenient method of mounting the infrared fiber optic light to the aircraft, the opening and recess are not necessary for operation of the infrared fiber optic light. The infrared fiber optic light can be formed in any shape or contour appropriate to the needs of a particular aircraft and mounted separately from any visible strobe light, if desired.
Although only a single solid-state infrared light source is required, several solid-state infrared light sources are included in the present invention for redundancy so that the light will continue to function if one light source should fail. The infrared light sources are optically coupled to a fiber optic cable. The fiber optic cable is arranged to provide a continuous band of infrared light, improving the visibility of the light.
The infrared light sources are electrically connected to a control circuit. The control circuit provides current-limited electrical power to the light sources. The control circuit also turns the infrared light sources on and off, providing bursts of infrared light in a regularly-timed pattern to attract the attention of other nearby covert aircraft and thereby prevent a collision hazard. The control circuit may be mounted within the housing structure, or may be located remotely.
Accordingly, it is an object of this invention to provide an infrared light for use on an aircraft that provides a distributed band of infrared light without the need for a large number of light sources. The invention overcomes this need for a large number of light sources by optically connecting the infrared light sources to a fiber optic cable. The fiber optic cable is arranged around the sidewall of the light. A control circuit flashes the infrared light sources on and off. The resulting bursts of light are distributed through the fiber optic cable, emitting an attention-getting band of infrared light.
The present invention comprises an infrared fiber optic light for use on an aircraft, comprising: a housing structure having an exterior surface; an infrared light source optically connected to a fiber optic cable, said infrared light source being located at said housing structure, and said fiber optic cable being arranged at said exterior surface and forming a continuous band for emission of infrared light beyond said infrared fiber optic light; and a control circuit for controlling the amount of electrical current applied to said infrared light source and regularly interrupting the electrical current to cause said infrared light source to flash.
These and other features will become better understood with reference to the following description, appended claims, and accompanying drawings.